The backbone forms the center of a human's body, and is the body part through which all nerves, transmitting instructions from the brain, pass. Thus, it is obvious that the health of the backbone is representative of the health of the entire body.
As the body ages, exercise is not conducted for a long time, or a person acquires a bad habit or poor posture in daily life, the backbone slowly bends leftwards, rightwards or forwards, so that overall health is worsened, and resistance to many diseases is lowered. In this case, a person may suffer from a ruptured disk, which is caused by abnormal protrusion of a spinal disk and causes pain due to pressure on spinal nerves, or scoliosis, which is the lateral deformation of the vertebral column.
As a method of treating the ruptured disk or scoliosis, a so-called “goldfish exercise” is known to people. The goldfish exercise is recommended especially for a person whose backbone is bent to the left or right. The goldfish exercise is conducted by bending the body leftwards or rightwards as if a person were a swimming goldfish, after he or she lies on his or her back. This exercise corrects the dislocation of the left and right sections of the backbone, eliminates pressure on spinal nerves or paralysis of peripheral nerves, makes the nervous function of the whole body uniform, and permits the smooth circulation of blood.
A conventional exercise apparatus using the above goldfish exercise has been proposed. Korean Patent Laid-Open Publication No. 10-2004-82234, which is entitled “Waist Strengthening Apparatus” and was published on Sep. 24, 2004, includes a straightening unit which shakes only an exerciser's buttocks leftwards and rightwards, in the state in which he or she is lying on his or her back. However, the straightening unit is problematic in that it shakes only the buttocks leftwards and rightwards in the state in which an exerciser is lying on his or her back, so that the shaking of the upper body is insufficient. That is, the main point of the goldfish exercise is to shake the upper body leftwards and rightwards. However, the conventional exercise apparatus exercises only the buttocks, so that there is little movement of the upper body.